class A:
    n1 = 200
    n2 = 400

    def fly(self):
        print("A-fly()")


class B(A):
    n1 = 200
    n2 = 400

    def fly(self):
        print("B-fly()")


class C(B):
    n1 = 100
    n2 = 400

    def fly(self):
        print("C-fly()")

    def say(self):
        print(self.n1)
        print(self.n2)
        print(self.n3)
        print(super().n1)
        print(B.n1)
        print(C.n1)
        self.fly()
        # 注意使用类型加方法名调用的时候需要传入self
        A.fly(self)
        super().fly()


c = C()
c.say()
